1. Field of the Invention
The present invention relates to the method of installing surface mount solar cells in the receiver plate section of a concentrator photovoltaic array. More specifically, the present invention relates to a configuration, and the associated manufacturing processes to provide a mounting surface, electrical interconnects, ancillary optical elements, passivation, and alignment of the foregoing, to facilitate the incorporation of surface mount (chip or wafer type devices in which the electrical contacts are located in a single plane, and are soldered or otherwise bonded to a mating plainer electrical contact forming simultaneously a physical and electrical attachment) solar cells into the receiver plate section of a concentrator photovoltaic array.
2. Prior Art
Several advantages can be realized by interposing a lens between the sun and a solar cell in a photovoltaic application. By the use of such a lens, the energy collected over a large area can be concentrated upon a single solar cell which will produce as much or more power than would be produced by a field of solar cells equal in area to that of the lens. Special solar cells have been developed which take advantage of the higher energy per unit area to convert this solar energy to electricity with greater efficiency than can be realized at the single sun level.
Despite the increased efficiency afforded by concentration, typically in the 50X to 500X concentration ratios, the majority of the incoming energy must be removed in the form of heat. To accomplish this feat, special care is given to the selection of materials and configuration of the receiver section, that portion of the solar array which collects, converts, and distributes the solar energy in the form of electricity. Previous arrays have been manufactured using heavy copper sheet laminated to an aluminum substrate with an intervening dielectric layer. The circuitry, which distributes the electricity from the solar cells which are soldered to this copper layer, is formed by chemically etching away all of the unwanted copper. The heavy copper and the dielectric materials including the adhesives used for lamination are selected to provide the maximum heat transfer, consistent with electrical isolation, from the copper circuitry to the aluminum substrate where it is dissipated by cooling fins attached to the back of the substrate which now becomes the receiver plate.
The copper, dielectric material, and adhesive are relatively expensive when compared to conventional etched circuit designs. Furthermore, the entire surface of the substrate must be covered with these expensive materials prior to defining the circuitry by etching. A very large fraction of the applied copper sheet is then converted to solution form which must be handled, as hazardous waste. If a pinhole failure should occur in the dielectric during the lamination process the entire receiver plate is lost. All of these factors add up to a high manufacturing cost for this technology.